U.S. Pat. No. 3,902,887 to Lin discloses a class of herbicidal s-triazines of the general formula: ##STR3## where X is oxygen or sulfur;
R.sub.1 is certain organic radicals including certain acyclic and cyclic radicals; PA1 R.sub.2 is hydrogen, lower alkyl, or certain cations; PA1 R.sub.3 is hydrogen or certain lower alkyls; and PA1 R.sub.4 is certain organic radicals; and various methods for synthesizing these compounds. PA1 R.sub.2 is alkyl of 1-4 carbon atoms. PA1 Q is hydrogen or chlorine; and PA1 R.sub.2 is alkyl of 1-4carbons.
Copending U.S. Pat. application No. 621,401, filed Oct. 10, 1975 by Adams et al., discloses and claims certain herbicidal 2-thiotriazinediones of the formula: ##STR4## wherein R.sub.1 is certain organic radicals, including certain aliphatic, alicyclic and aromatic radicals, and
In addition, U.S. Ser. No. 621,401, discloses two processes for preparing those 2-thio compounds, one of which involves the reaction of phosgene with a cyanimide, followed by reaction with a substituted thiourea, which process is, in part, the subject of the present application.